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Query: UNIPROT:P06889 (Mol)
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The uxuAB operon is composed of two genes coding for enzymes involved in hexuronate degradation. This operon is negatively controlled by the uxuR and exuR regulatory gene products. Starting from uxu hybrid plasmids, a 300 bp Sau3A restriction fragment was isolated and shown to contain the entire uxu regulatory region using in vitro gene fusions that brought lac gene expression under the control of the transcriptional and translational signals of the uxuA gene. The nucleotide sequence of this fragment was established. The start of the uxu mRNA was localized by S1 mapping experiments (the presence of a CAP binding site upstream of the promoter was shown by DNAse I footprinting and in vitro titration). The N-terminal amino acid sequence of the purified uxuA-lacZ gene product allowed the mapping of the uxuA initiation codon at 115 bp from the start of transcription.
Mol Gen Genet 1986 Jan
PMID:The regulatory region of the uxuAB operon in Escherichia coli K12. 308 15

The mglB gene of Salmonella typhimurium LT2 coding for the galactose-binding protein (GBP) was sequenced. We compared the deduced amino acid sequence with the GBP sequence of Escherichia coli K 12. The mature proteins differ in only 19 of 309 amino acid residues, corresponding to 94% homology. Analysis of the mglB control region by promoter-probe vectors revealed that two promoters, P1 and P2, constitute the mgl control region (Pmgl). P1 and P2 function in a synergistic way. P1 is the main promoter of the operon; its activity is 20 times the activity of P2. Both promoters are activated by the cyclic adenosine monophosphate catabolite activator protein (cAMP/CAP) complex. While P1 is inactive in the absence of the cAMP/CAP complex, there is residual activity of P2 under these conditions. Studies on the inducibility of the mglBAEC operon using multicopy plasmid promoter-probe vectors were hampered by the titration of the mgl repressor resulting in a partially constitutive expression of the mgl operon. The results indicate that only P1 is responding to induction by D-fucose. A weak promoter, PD, within the P1 region but divergent to it was found. PD is neither stimulated by the cAMP/CAP complex nor by D-fucose. We cloned the gene located downstream to PD and found it to strongly repress the expression of the mgl operon. We termed this gene mglD. The presence of D-fucose abolished the repression caused by the plasmid-encoded mglD gene product.
Mol Gen Genet 1988 Nov
PMID:The mglB sequence of Salmonella typhimurium LT2; promoter analysis by gene fusions and evidence for a divergently oriented gene coding for the mgl repressor. 314 19

Three pairs of mouse CAP-R PYR-IND OLI-R mitochondrial mutants, and the corresponding CAP-S parental lines, were assayed to determine if cellular expression of these phenotypes was accompanied by changes in cellular energy metabolism: glycolysis, cellular respiration, citric acid cycle activity, and mitochondrial electron transport. Relative to its parental CAP-S line, the SVT2 CAP-R mutant had no significant deficiencies in any of the pathways analyzed. In contrast, the LA9 and SVA31 CAP-R mutants showed significant reductions in cellular respiration. At the biochemical level, respiration deficiency was accompanied by derangements in mitochondrial electron transport. It was also found that the CAP-R mutants had very high levels of glycolysis when the cells were maintained in the presence of chloramphenicol. The possibility is discussed that the sequence changes in the mitochondrial large rRNA gene which determine chloramphenicol resistance can also result, at least in some cases, in reduced levels of mitochondrial biogenesis, leading to respiration deficiency. The PYR-IND and OLI-R phenotypes, which also appear to be encoded by the CAP-R mutations, may result from a compensatory increase in glycolysis-generated ATP or metabolic intermediates.
Somat Cell Mol Genet 1988 Mar
PMID:Mitochondrial chloramphenicol-resistant mutants can have deficiencies in energy metabolism. 316 37

Members of the Spec gene family are expressed during embryonic development of the sea urchin, Strongylocentrotus purpuratus. The family encodes proteins related to the calmodulin/troponin C/myosin light chain group of calcium binding proteins and one gene, Spec1, has been studied extensively in our laboratory. In this paper, we analyze other members of the family, collectively termed Spec2 genes. We make use of several hybridization probes derived from Spec1 and Spec2 cDNA clones, which recognize different members of the family. Genomic DNA gel blot and slot blot analyses show that there are approximately eight Spec genes in the S. purpuratus genome. The structures of three Spec2 genes, Spec2a, Spec2c and Spec2d, are described. A 60 kb (kb = 10(3) bases or base-pairs) region of the genome contains the linked Spec1-Spec2c genes and two separate 20 kb regions contain the Spec2a and Spec2d genes. Six members of a repetitive sequence family are dispersed at various locations among the genes. The transcriptional initiation sites of the three Spec2 genes are mapped, and 400 to 500 base-pairs of 5'-flanking DNA sequenced. All three Spec2 genes initiate transcription approximately 120 base-pairs upstream from the 3' end of the first exon. In contrast, the 5' end of the Spec1 transcript begins about 107 base-pairs farther upstream, so it contains 5' untranslated sequences that correspond to non-transcribed 5'-flanking sequences of the Spec2 genes. There is little similarity among the sequences upstream from the CAP site of the Spec2 genes except the TATA consensus sequence and a repeating trinucleotide, AAC. Measurements of Spec mRNA levels during embryogenesis show that Spec1 mRNA begins to accumulate at the early blastula stage and is the most abundant; Spec2a/Spec2c mRNAs begin accumulating several hours later at the late blastula-early gastrula stage and reach about 40 to 60% the levels of Spec1; and Spec2d mRNAs accumulate mostly during the gastrula and pluteus stages with levels reaching only 2% those of Spec1. In situ hybridization with probes that recognize either all Spec2 mRNAs or only Spec2d mRNAs show that, like Spec1, these mRNAs are restricted to aboral ectoderm cells and their precursors. The Spec gene family represents a group of related genes whose mRNAs all accumulate in the same cell type but at different times and to different levels during embryogenesis.
J Mol Biol 1988 Aug 05
PMID:Spec2 genes of Strongylocentrotus purpuratus. Structure and differential expression in embryonic aboral ectoderm cells. 317 23

The nucleotide sequence of the putC region, from which divergent transcription of the putP and putA genes starts, was determined. The promoter region for the putA gene was restricted to the location between the HindIII site and the NcoI site or at the NcoI site by using putA-lacZ fusion plasmids and the transcriptional start for the putA gene was identified in the region between the HindIII site and the NcoI site by Sl mapping. This region also contains a potential CAP binding site, a ribosome binding site, and a sequence that is highly homologous to argTr. Five potential promoters (putPp1-putPp5) for the putP gene, which were separate from the promoter region for the putA gene, were indicated by S1 mapping analysis of the putP gene transcripts. We concluded that the putC region is 419 bp long and contains two independent sets of promoters, regulating the expression of putP and putA genes in opposite directions. In addition, this region was found to contain an open reading frame (orf) capable of encoding a polypeptide of 111 amino acids in overlapping fashion. But studies using an orf-lacZ fusion gene showed that this open reading frame was not expressed.
Mol Gen Genet 1987 Dec
PMID:Nucleotide sequence of putC, the regulatory region for the put regulon of Escherichia coli K12. 332 81

The suppression of temperature sensitive phenotype caused by mutation rho ts 15, making cells deficient in transcription termination, but mutation crp11 impairing the cAMP-receptor protein (cap) restores transcription termination on IS3 sequence in galactose operon and on the site before the promoter of udp gene in strains crp11 rho ts15. The obtained data suggest the direct interaction between factor Rho and cAMP-CAP complex in transcription process.
Mol Gen Mikrobiol Virusol 1986 May
PMID:[Effect of mutation crp11 in the 3',5'-cyclic adenosine monophosphate receptor on the expression of the udp gene in Escherichia coli K12 strains deficient for transcription termination factors (rho ts15)]. 354 Jun 40

The sigma subunits of bacterial RNA polymerases are required for the selective initiation of transcription. We have isolated and characterized mutations in rpoD, the gene which encodes the major form of sigma in E. coli, which affect the selectivity of transcription. These mutations increase the expression of araBAD up to 12-fold in the absence of CAP-cAMP. Expression of lac is unaffected, while expression of malT-activated operons is decreased. We determined the DNA sequence of 17 independently isolated mutations, and found that they consist of three different changes in a single CGC arginine codon at position 596 in the sigma polypeptide.
Mol Gen Genet 1985
PMID:Mutations in the sigma subunit of E. coli RNA polymerase which affect positive control of transcription. 388 51

In Escherichia coli, 3'5'-adenosine cyclic monophosphate (cAMP) and its receptor protein (CAP) are known to be involved in the control of transcription initiation of catabolic operons. In previous papers we have shown that the cAMP-CAP complex is also involved as a modulator of polarity in polycistronic transcription units. Furthermore we showed that there exists a functional relationship between this complex and the transcription termination protein, Rho. In this work, we measured mRNA synthesis corresponding to the promoter proximal and distal parts of the lac and gal operons by DNA-RNA hybridization. We show that in these operons the main polarity effect is essentially transcriptional and the cAMP-CAP complex decreases polarity by interfering with premature transcription termination.
Mol Gen Genet 1984
PMID:Transcriptional control of polarity in Escherichia coli by cAMP. 609 68

The regulatory protein CRP (or CAP) from E. coli is shown to display two distinct patterns of binding interactions with DNA-dependent RNA polymerase. The free core enzyme, and both the core and the holo polymerase when bound to single-stranded DNA, can bind CRP in a cAMP-independent association reaction. Instead, the binding of CRP to free holoenzyme and to holo or core polymerase bound to native DNA was undetectable in the absence of cAMP. The specific ligand of CRP (cAMP) strengthens distinctively this class of interactions. In no case could any release of sigma-factor be demonstrated. Estimates of the dissociation constants were obtained for the various binding reactions which were investigated under quasi-physiological ionic conditions. These, together with the known values of the in vivo concentrations of CRP and RNA polymerase, suggest that the interactions described may have a functional significance.
Mol Biol Rep 1980 Mar 31
PMID:Binding of CRP to DNA-dependent RNA polymerase from E. coli: modulation by cAMP of the interactions with free and DNA-bound holo and core enzyme. 624 68

We attempted to correlate structural modifications of the adenosine 3',5' cyclic monophosphate (cAMP) receptor protein (CAP), to changes in some of its in vivo regulatory functions such as (i) stimulation of the lactose operon expression and (ii) control of adenylate cyclase activity. A radioimmunological procedure was used to study the structure of CAP synthesized by three mutants (crpX) grown under various conditions, in the presence or absence of endogenous or exogenous cAMP. In one mutant CAP appears to be sensitive to thermal inactivation. In another mutant CAP is particularly sensitive to degradation in the absence of cAMP; this degradation is enhanced by high temperature and during stationary phase of growth, and prevented by the addition of glucose. Functional alterations of CAP were not found to follow structural changes strictly. In the crpX mutants and in strains carrying the crp+ or other crp allele, the stimulation of the lactose operon expression and the modulation of the in vivo rates of cAMP synthesis appear to vary in parallel, favoring an indirect mechanism of regulation of adenylate cyclase by CAP.
Mol Gen Genet 1982
PMID:crpX mutants of Escherichia coli K12: specific regulatory effects of altered cyclic AMP receptor proteins. 629 64


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